Read the following statements and select the incorrect statement :-

Options

A. The colonies of cyanobacteria are generally surrounded by gelatinous sheath
B. The cyanobacteria are unicellular, colonial or filamentous, freshwater/marine or terrestrial.
C. Rhizopus belongs to class phycomycetes of kingdom fungi
D. Bacteria are grouped under two categories only based on their shape

Answer

To solve the question, we need to analyze the statements provided and identify the incorrect one.

### Step-by-Step Solution:

1. **Examine the First Statement**:
- "The colonies of the cyanobacteria are generally surrounded by a gelatinous sheath."
- This statement is true. Cyanobacteria, such as Nostoc and Anabaena, often form colonies that are surrounded by a protective gelatinous sheath.

2. **Examine the Second Statement**:
- "Rhizopus belongs to the class Phycomyces of kingdom fungi."
- This statement is also true. Rhizopus is a type of mold that falls under the Phycomycetes class, which is part of the kingdom Fungi.

3. **Examine the Third Statement**:
- "Bacteria are grouped under two categories based only on their shape."
- This statement is incorrect. Bacteria are classified into four primary shapes: Cocci (spherical), Bacilli (rod-shaped), Spirilla (spiral), and Vibrios (comma-shaped). Therefore, stating that they are grouped into only two categories is false.

4. **Examine the Fourth Statement**:
- Since the third statement is incorrect, we can conclude that this is the answer to the question.

### Conclusion:
The incorrect statement is: "Bacteria are grouped under two categories based only on their shape."

Thus, the answer is option number 4.

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